William H Edwards

Incidence, presenting features, risk factors and significance of late onset septicemia in very low birth weight infants

BACKGROUNDnSepticemia is a major antecedent of morbidity and mortality in very low birth weight (501- to 1500-g) infants. Our purpose was to determine prospectively the incidence, clinical presentation, laboratory features, risk factors, morbidity and mortality associated with late onset septicemia in infants 501 to 1500 g.nnnMETHODSnClinical data were prospectively collected for 2416 infants enrolled in a multicenter trial to determine the efficacy of intravenous immunoglobulin in preventing nosocomial infections. Septicemia was confirmed by positive blood culture in 395 symptomatic infants. Multivariate analyses of factors associated with septicemia were performed.nnnRESULTSnSixteen percent of VLBW infants developed septicemia at a median age of 17 days. Factors associated with septicemia by logistic regression included male gender, lower gestational age and birth weight and decreased baseline serum IgG concentrations. Increasing apnea (55%), feeding intolerance, abdominal distension or guaiac-positive stools (43%), increased respiratory support (29%), lethargy and hypotonia (23%) were the dominant presenting features of septicemia. An abnormal white blood cell count (46%), unexplained metabolic acidosis (11%) and hyperglycemia (10%) were the most common laboratory indicators. Septicemic infants, compared with nonsepticemic infants, had significantly increased mortality (21% vs. 9%), longer hospital stay (98 vs. 58 days) and more serious morbidity, including severe intraventricular hemorrhage, bronchopulmonary dysplasia and increased ventilator days (P < 0.001).nnnCONCLUSIONSnLate onset septicemia is common in very low birth weight infants, and the rate is inversely proportional to gestational age and birth weight. Septicemia is more common in males and those with low initial serum IgG values. A set of clinical signs (apnea, bradycardia, etc.) and laboratory values (leukocytosis, immature white blood cells and neutropenia) increase the probability of late onset sepsis, but they have poor positive predictive value.

A controlled trial of intravenous immune globulin to reduce nosocomial infections in very-low-birth-weight infants

BACKGROUNDnNosocomial infections are a major cause of morbidity and mortality in premature infants. As a rule, their low serum gamma globulin levels at birth subsequently decline to hypogammaglobulinemic values; hence, prophylactic administration of intravenous immune globulin may reduce the rate of hospital-acquired infections.nnnMETHODSnIn this prospective, multicenter, two-phase controlled trial, 2416 infants were stratified according to birth weight (501 to 1000 g and 1001 to 1500 g) and randomly assigned to an intravenous immune globulin group (n = 1204) or a control group (n = 1212). Control infants were given placebo infusions during phase 1 of the study (n = 623) but were not given any infusions during phase 2 (n = 589). Infants weighing 501 to 1000 g at birth were given 900 mg of immune globulin per kilogram of body weight, and infants weighing 1001 to 1500 g at birth were given a dose of 700 mg per kilogram. The immune globulin infusions were repeated every 14 days until the infants weighed 1800 g, were transferred to another center, died, or were sent home from the hospital.nnnRESULTSnNosocomial infections of the blood, meninges, or urinary tract occurred in 439 of the 2416 infants (18.2 percent): 208 (17.3 percent) in the immune globulin group and 231 (19.1 percent) in the control group (relative risk, 0.91; 95 percent confidence interval, 0.77 to 1.08). Septicemia occurred in 15.5 percent of the immune globulin recipients and 17.2 percent of the controls. During phase 1 the rate of nosocomial infections was 13.4 percent in the immune globulin group and 17.8 percent in the control group; the respective rates during phase 2 were 21.0 percent and 20.4 percent. The predominant organisms included gram-positive cocci (53.0 percent), gram-negative bacilli (22.4 percent), and candida species (16.0 percent). Adverse reactions were rarely observed during the infusions. Immune globulin therapy had no effect on respiratory distress syndrome, bronchopulmonary dysplasia, intracranial hemorrhage, the duration of hospitalization, or mortality. The incidence of necrotizing enterocolitis was 12.0 percent in the immune globulin group and 9.5 percent in the control group.nnnCONCLUSIONSnProphylactic use of intravenous immune globulin failed to reduce the incidence of hospital-acquired infections in very-low-birth-weight infants.

The Vermont Oxford Network: a community of practice.

The Vermont Oxford Network is a not-for-profit organization established in the late 1980s with the goals of improving the quality and safety of medical care for newborn infants and their families through a coordinated program of research, education, and quality improvement. In this paper the authors discuss the activities and programs sponsored by the Network to achieve those goals.

Premedication for Nonemergent Neonatal Intubations: A Randomized, Controlled Trial Comparing Atropine and Fentanyl to Atropine, Fentanyl, and Mivacurium

OBJECTIVE. The purpose of this work was to investigate whether using a muscle relaxant would improve intubation conditions in infants, thereby decreasing the incidence and duration of hypoxia and time and number of attempts needed to successfully complete the intubation procedure. PATIENTS/METHODS. This was a prospective, randomized, controlled, 2-center trial. Infants requiring nonemergent intubation were randomly assigned to receive atropine and fentanyl or atropine, fentanyl, and mivacurium before intubation. Incidence and duration of hypoxia were determined at oxygen saturation thresholds of ≤85%, ≤75%, ≤60%, and ≤40%. Videotape was reviewed to determine the time and number of intubation attempts and duration of action of mivacurium. RESULTS. Analysis of 41 infants showed that incidence of oxygen saturation ≤60% of any duration was significantly less in the mivacurium group (55% vs 24%). The incidence of saturation level of any duration ≤85%, 75%, and 40%; cumulative time ≥30 seconds; and time below the thresholds were not significantly different. Total procedure time (472 vs 144 seconds) and total laryngoscope time (148 vs 61 seconds) were shorter in the mivacurium group. Successful intubation was achieved in ≤2 attempts significantly more often in the mivacurium group (35% vs 71%). CONCLUSIONS. Premedication with atropine, fentanyl, and mivacurium compared with atropine and fentanyl without a muscle relaxant decreases the time and number of attempts needed to successfully intubate while significantly reducing the incidence of severe desaturation. Premedication including a short-acting muscle relaxant should be considered for all nonemergent intubations in the NICU.

Candles in the Snow: Ritual and Memory for Siblings of Infants Who Died in the Intensive Care Nursery

OBJECTIVEnTo assess the developmental impact of surviving a sibling who dies in the neonatal intensive care unit (NICU).nnnSTUDY DESIGNnFourteen (13 adults, 1 adolescent) siblings of infants who died in Dartmouth-Hitchcock Medical Centers NICU between 1980 and 1990 were interviewed. The interviews were recorded and transcribed verbatim, and prominent themes were coded.nnnRESULTSnSix siblings rated family communication as veiled or a family secret; 7 reported unresolved parental mourning. Eleven siblings were rated high on anxiety themes, including concerns over future pregnancy or anxiety about their mothers health. Photos and family rituals were helpful to siblings in grieving and remembering the infant.nnnCONCLUSIONSnAlthough death in the NICU often has a brief course, consequences for survivor siblings can be life-long. Siblings born both before and after the death of an infant may be at risk and in need of psychological support. Family rituals and photos are important vehicles of communication, grieving, and memory for siblings and parents alike. Clinicians should allow siblings to be active participants in the infants brief life and death.

Central line-associated bloodstream infections in neonatal intensive care: changing the mental model from inevitability to preventability.

Previously considered unavoidable complications of hospital care (reflecting an entitlement mental model), health care-associated infections are now considered as medical errors and cause significant preventable morbidity and mortality in neonates. Prevention of such infections, particularly central line-associated bloodstream infections (CLABSI), should be an important patient safety priority for all neonatal intensive care units (NICUs). An important first step is to promote a mental model of CLABSIs as preventable complications of care. Other general strategies are (1) promoting an organizational culture of safety and empowerment of staff; (2) hand hygiene; (3) avoiding overcrowding and understaffing; (4) using breast milk for enteral feedings; and (5) involving families in infection prevention efforts. Specific strategies to prevent CLABSI are (1) insertion practices: insertion of all central vascular catheters under strict sterile conditions with the aid of a checklist; (2) maintenance practices: ensuring that entries into the lumen of the vascular catheter always occur under aseptic conditions, minimizing catheter disconnections, and replacement of intravenous infusion sets at recommended intervals; (3) removal of all central lines as soon as possible. Participation in national or statewide quality improvement collaboratives is an emerging trend in neonatology that can enhance CLABSI prevention efforts by NICUs.

1699 A TRANSMISSION ELECTRON MICROSCOPY STUDY OF HUMAN CEREBRAL CORTICAL AND GERMINAL MATRIX (GM) BLOOD VESSELS IN PREMATURE NEONATES

Intracranial hemorrhage in premature human neonates is a major cause of mortality and morbidity. The hemorrhage usually originates in the GM over the caudate nucleus. Although structural susceptibility of the GM blood vessels to neonatal stress has been suggested as a cause for hemorrhage, histological confirmation is lacking. Because cortical hemorrhage in prematures is less frequent, we compared the ultrastructural morphology of blood vessels in the GM with those of the cerebral cortex. We studied prematures of 22-27 weeks gestation with and without GM and intraventricular hemorrhage. Autopsy materials were obtained less than 2 hours postmortem, fixed in glutaraldehyde and examined by transmission electron microscopy.Our observations are that the cortical blood vessels uniformly have mature characteristics: continuous basal lamina, tight junctions, absence of fenestrations and complete pericytic encirclement. In the GM, however, there were 2 types of blood vessels. One type resembled the cortical vessels with all the characteristics of maturity. The second type had all the characteristics of immature blood vessels: presence of fenestrations and absence of a continuous basal lamina, tight junctions, and full encirclement by pericytes.We postulate that the presence of structurally immature blood vessels in the GM makes this area more susceptible to hemorrhage.

The New Hampshire Perinatal Program: twenty years of perinatal outreach education.

OBJECTIVE:To describe 20 years of regional outreach education by the New Hampshire Perinatal Program, its interaction with all 26 community hospitals in the state with maternity services and an additional four in adjoining Vermont.STUDY DESIGN:This paper describes educational initiatives responsive to the needs of perinatal physicians and nurses. The core of the program is the transport conference held annually at each referring hospital in which maternal–fetal and infant referrals are discussed. There are additional community hospital-based programs, programs at convenient locations in the region and medical center conferences and skills programs.RESULTS:The program annually awards 10,000 continuing medical education credits (CME) and nursing contact hours. Evaluation and feedback from all participants is encouraged. New Hampshire has one of the lowest perinatal mortality rates in the county, which reflects in part the accomplishments of the program.CONCLUSION:Perinatal outreach education is a shared responsibility of providers in both the academic center and community hospitals and is necessary to ensure optimal care for mothers and infants.

MORTALITY AFTER DISCHARGE FROM NEONATAL INTENSIVE CARE

Mortality rates for neonatal intensive care units are often reported as neonatal deaths (<28 days) or deaths prior to discharge from the unit. We investigated deaths occurring after discharge from our intensive care nursery (ICN). Of 1,978 admissions to the Dartmouth-Hitchcock Medical Center ICN for the years 1976-1981, 225 infants died prior to discharge (11.4%). We matched the remaining 1,753 infants with New Hampshire and Vermont death records. We identified 40 post discharge deaths; 33 occurred at age <1 year. Causes of death are recorded below.Seven of the 8 SIDS infants were premature (out of 1,234 prematures discharged); 6 of the 8 were male; 3 were one of twins. Apnea was identified prior to discharge in only 4 of the SIDS group. Significant pathology in the SIDS group related to the neonatal course included periventricular leukomalacia with cerebellar atrophy, laryngeal fibrosis with stenosis and bronchopulmonary dysplasia.

The Effects of Acute Total Asphyxia and Metabolic Acidosis on Cerebrospinal Fluid Bicarbonate Regulation in Newborn Puppies

Summary: We evaluated CSF [HCO3-] regulation in lightly anesthetized newborn puppies following: (1) acute total asphyxia; (2) metabolic acidosis; and (3) metabolic acidosis induced after acute asphyxia. Five and one-half min of total asphyxia resulted in a 4.4 mM/liter decrease in mean CSF [HCO3-]. During 65 min of recovery with mechanical ventilation mean CSF [HCO3-] increased 1.7 mM/liter. Mean plasma [HCO3-] decreased 7 mM/liter and recovered 4.5 mM/liter in the same period. We produced a stable metabolic acidosic for 4 hr using a peritoneal dialysis technique with PaCO2 maintained at the normal value. With acidosis in nonasphyxiated control puppies, CSF [HCO3-] decreased steadily. At 4 hr, the ratio, ΔCSF [HCO3-]/Δplasma [HCO3-], was 0.43, a value close to that observed in adults of many species with metabolic acid-base disturbances, 0.41. With acidosis in asphyxiated puppies allowed 1 hr of recovery, the time course and mean values of plasma and CSF [HCO3-] were indistinguishable from those of the nonasphyxiated acidotic controls. Newborn puppies appear to regulate CSF [HCO3-] in response to acute asphyxia or metabolic acidosis, and acute asphyxia does not impair the puppys ability to regulate CSF [HCO3-] in metabolic acidosis.Speculation: The puppy can regulate CSF [HCO3-] in two stresses which occur commonly in the newborn period, birth asphyxia, and metabolic acidosis. This ability would help to preserve normal acid-base balance in the central nervous system during these stresses.